From time to time I get asked:
"What is the difference between the K3LR 160 parasitic array and a
textbook fullsize no compromise 4 square"?
That is a great question
The difference is bandwidth of performance
The four square has VSWR control to the TX and gain/FB parameters that
hold up better over the band.
As you can see from the excellent work that Greg, W8WWV did - the
performance of the K3LR array is narrow and for best results the K3LR
array has to be adjusted (parasitics and matching) to move between CW
and SSB areas.
When the K3LR array is in its sweet spot the forward gain is slightly
less that a good 4 square, however the F/B can be 10 dB better with the
K3LR array (over a narrow bandwidth).
73
Tim K3LR
On 2026-07-20 07:35, w5znjoel--- via Topband wrote:
I built my K3LR 160 TX array 8 years ago and have not once regretted
the
investment in time to construct it. If you are considering this array,
I
will offer one point that is extremely important. While the base
insulated
tower (driven element) and parasitic elements are relatively easy to
erect
do NOT skimp or cut corners on the radial field. That consumed almost
90% of
the time for me to construct this array. Follow the process Tim used,
described in Low Band DX'ing, for radials.
The work performed by W8WWV on this array is extremely valuable
information.
Even though it was published after my array had been in operation for a
few
years it provided additional insight to a couple of items I had noted
in my
experience with the array but didn't completely understand. If you have
one
of these arrays and haven't studied Greg's paper, or you're considering
constructing one, do so!
73 Joel W5ZN
-----Original Message-----
From: Topband <[email protected]> On
Behalf
Of Tim Duffy
Sent: Monday, July 20, 2026 1:22 AM
To: 'Rob Atkinson' <[email protected]>; [email protected]
Subject: Re: Topband: The Big Guys
Speaking of base fed insulated towers on 160... that happen to be 90
degrees
high (about 120 feet) - by design... I have had this for over 30 years
- it
is what I think is the best vertical antenna array for 160 that I have
found. Bandwidth performance is narrow - but it tunes up easy and it
really
works. AA1K, VE3EJ, K9CT, W5ZN and NR5M and others all use the K3LR
Yagi
vertical design. WA3FET and K3LC worked with me on the early designs.
This is a very effective gain antenna (almost 6 dB) with good front to
back
ratio (30 dB and can be used on RX with attn.) is described in editions
3,4
and 5 of the ON4UN Low Band DXing book by ARRL. Only takes a single 120
foot
tower (all tower sections must be Cad welded together). It is a Three
element vertical parasitic beam (shoots in four directions). BUT needs
FIVE
radial systems of 1/4 wavelength radials... I use 120 radials per
element -
one quarter wavelength long - 130 feet.
The most recent version of this antenna has been updated by work (28
pages)
from Greg, W8WWV here:
https://www.k3lr.com/engineering/160m/K3LR160m2024Revisit.pdf
This is currently what is in use at K3LR. Twice this array/station at
K3LR
worked more than one hundred countries in a single CQWW CW weekend on
160
(48 hour contest).
We have just installed a brand new broadcast style radial system (all
silver
soldered) for all five vertical elements - this summer of 2026 (old one
was
35 years old). Thanks W3YQ for engineering the installed solution.
The performance is spectacular.
73
Tim K3LR
-----Original Message-----
From: Topband [mailto:[email protected]] On
Behalf Of Rob Atkinson via Topband
Sent: Sunday, July 19, 2026 8:29 PM
To: [email protected]
Subject: Re: Topband: The Big Guys
you can have a broadcast tower that's too tall for 160 m. which results
in
high angle lobes. For this to work well you need one for a station
that's
up near the top of the broadcast band. A good way to tell is whether
or not
the tower is lamped. The ground system certainly helps but a ham can
put in
a good ground system on his own monopole. Don't believe that only
broadcasters can do this, although nowadays a lot of radials on 160
costs a
lot more than they did 25 years ago. These antennas will likely stink
on
receive. You'll just pick up noise. Expect to have to set up some
sort of
separate receive arrangement. By the way, there are and have been a
few
hams with base fed insulated towers and ground systems on 160. They
don't
chase DX or contest so you may not have run across them.
73
Rob
K5UJ
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